drivers/gpu/drm/bridge/nxp-ptn3460.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * NXP PTN3460 DP/LVDS bridge driver
   4  *
   5  * Copyright (C) 2013 Google, Inc.
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/i2c.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <drm/drm_atomic_helper.h>
  14 #include <drm/drm_bridge.h>
  15 #include <drm/drm_crtc.h>
  16 #include <drm/drm_edid.h>
  17 #include <drm/drm_of.h>
  18 #include <drm/drm_panel.h>
  19 #include <drm/drm_print.h>
  20 #include <drm/drm_probe_helper.h>
  21
  22 #define PTN3460_EDID_ADDR                       0x0
  23 #define PTN3460_EDID_EMULATION_ADDR             0x84
  24 #define PTN3460_EDID_ENABLE_EMULATION           0
  25 #define PTN3460_EDID_EMULATION_SELECTION        1
  26 #define PTN3460_EDID_SRAM_LOAD_ADDR             0x85
  27
  28 struct ptn3460_bridge {
  29         struct drm_connector connector;
  30         struct i2c_client *client;
  31         struct drm_bridge bridge;
  32         struct edid *edid;
  33         struct drm_panel *panel;
  34         struct gpio_desc *gpio_pd_n;
  35         struct gpio_desc *gpio_rst_n;
  36         u32 edid_emulation;
  37         bool enabled;
  38 };
  39
  40 static inline struct ptn3460_bridge *
  41                 bridge_to_ptn3460(struct drm_bridge *bridge)
  42 {
  43         return container_of(bridge, struct ptn3460_bridge, bridge);
  44 }
  45
  46 static inline struct ptn3460_bridge *
  47                 connector_to_ptn3460(struct drm_connector *connector)
  48 {
  49         return container_of(connector, struct ptn3460_bridge, connector);
  50 }
  51
  52 static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
  53                 u8 *buf, int len)
  54 {
  55         int ret;
  56
  57         ret = i2c_master_send(ptn_bridge->client, &addr, 1);
  58         if (ret <= 0) {
  59                 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
  60                 return ret;
  61         }
  62
  63         ret = i2c_master_recv(ptn_bridge->client, buf, len);
  64         if (ret <= 0) {
  65                 DRM_ERROR("Failed to recv i2c data, ret=%d\n", ret);
  66                 return ret;
  67         }
  68
  69         return 0;
  70 }
  71
  72 static int ptn3460_write_byte(struct ptn3460_bridge *ptn_bridge, char addr,
  73                 char val)
  74 {
  75         int ret;
  76         char buf[2];
  77
  78         buf[0] = addr;
  79         buf[1] = val;
  80
  81         ret = i2c_master_send(ptn_bridge->client, buf, ARRAY_SIZE(buf));
  82         if (ret <= 0) {
  83                 DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
  84                 return ret;
  85         }
  86
  87         return 0;
  88 }
  89
  90 static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
  91 {
  92         int ret;
  93         char val;
  94
  95         /* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
  96         ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
  97                         ptn_bridge->edid_emulation);
  98         if (ret) {
  99                 DRM_ERROR("Failed to transfer EDID to sram, ret=%d\n", ret);
 100                 return ret;
 101         }
 102
 103         /* Enable EDID emulation and select the desired EDID */
 104         val = 1 << PTN3460_EDID_ENABLE_EMULATION |
 105                 ptn_bridge->edid_emulation << PTN3460_EDID_EMULATION_SELECTION;
 106
 107         ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_EMULATION_ADDR, val);
 108         if (ret) {
 109                 DRM_ERROR("Failed to write EDID value, ret=%d\n", ret);
 110                 return ret;
 111         }
 112
 113         return 0;
 114 }
 115
 116 static void ptn3460_pre_enable(struct drm_bridge *bridge)
 117 {
 118         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 119         int ret;
 120
 121         if (ptn_bridge->enabled)
 122                 return;
 123
 124         gpiod_set_value(ptn_bridge->gpio_pd_n, 1);
 125
 126         gpiod_set_value(ptn_bridge->gpio_rst_n, 0);
 127         usleep_range(10, 20);
 128         gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
 129
 130         if (drm_panel_prepare(ptn_bridge->panel)) {
 131                 DRM_ERROR("failed to prepare panel\n");
 132                 return;
 133         }
 134
 135         /*
 136          * There's a bug in the PTN chip where it falsely asserts hotplug before
 137          * it is fully functional. We're forced to wait for the maximum start up
 138          * time specified in the chip's datasheet to make sure we're really up.
 139          */
 140         msleep(90);
 141
 142         ret = ptn3460_select_edid(ptn_bridge);
 143         if (ret)
 144                 DRM_ERROR("Select EDID failed ret=%d\n", ret);
 145
 146         ptn_bridge->enabled = true;
 147 }
 148
 149 static void ptn3460_enable(struct drm_bridge *bridge)
 150 {
 151         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 152
 153         if (drm_panel_enable(ptn_bridge->panel)) {
 154                 DRM_ERROR("failed to enable panel\n");
 155                 return;
 156         }
 157 }
 158
 159 static void ptn3460_disable(struct drm_bridge *bridge)
 160 {
 161         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 162
 163         if (!ptn_bridge->enabled)
 164                 return;
 165
 166         ptn_bridge->enabled = false;
 167
 168         if (drm_panel_disable(ptn_bridge->panel)) {
 169                 DRM_ERROR("failed to disable panel\n");
 170                 return;
 171         }
 172
 173         gpiod_set_value(ptn_bridge->gpio_rst_n, 1);
 174         gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
 175 }
 176
 177 static void ptn3460_post_disable(struct drm_bridge *bridge)
 178 {
 179         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 180
 181         if (drm_panel_unprepare(ptn_bridge->panel)) {
 182                 DRM_ERROR("failed to unprepare panel\n");
 183                 return;
 184         }
 185 }
 186
 187 static int ptn3460_get_modes(struct drm_connector *connector)
 188 {
 189         struct ptn3460_bridge *ptn_bridge;
 190         u8 *edid;
 191         int ret, num_modes = 0;
 192         bool power_off;
 193
 194         ptn_bridge = connector_to_ptn3460(connector);
 195
 196         if (ptn_bridge->edid)
 197                 return drm_add_edid_modes(connector, ptn_bridge->edid);
 198
 199         power_off = !ptn_bridge->enabled;
 200         ptn3460_pre_enable(&ptn_bridge->bridge);
 201
 202         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 203         if (!edid) {
 204                 DRM_ERROR("Failed to allocate EDID\n");
 205                 return 0;
 206         }
 207
 208         ret = ptn3460_read_bytes(ptn_bridge, PTN3460_EDID_ADDR, edid,
 209                         EDID_LENGTH);
 210         if (ret) {
 211                 kfree(edid);
 212                 goto out;
 213         }
 214
 215         ptn_bridge->edid = (struct edid *)edid;
 216         drm_connector_update_edid_property(connector, ptn_bridge->edid);
 217
 218         num_modes = drm_add_edid_modes(connector, ptn_bridge->edid);
 219
 220 out:
 221         if (power_off)
 222                 ptn3460_disable(&ptn_bridge->bridge);
 223
 224         return num_modes;
 225 }
 226
 227 static const struct drm_connector_helper_funcs ptn3460_connector_helper_funcs = {
 228         .get_modes = ptn3460_get_modes,
 229 };
 230
 231 static const struct drm_connector_funcs ptn3460_connector_funcs = {
 232         .fill_modes = drm_helper_probe_single_connector_modes,
 233         .destroy = drm_connector_cleanup,
 234         .reset = drm_atomic_helper_connector_reset,
 235         .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 236         .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 237 };
 238
 239 static int ptn3460_bridge_attach(struct drm_bridge *bridge)
 240 {
 241         struct ptn3460_bridge *ptn_bridge = bridge_to_ptn3460(bridge);
 242         int ret;
 243
 244         if (!bridge->encoder) {
 245                 DRM_ERROR("Parent encoder object not found");
 246                 return -ENODEV;
 247         }
 248
 249         ptn_bridge->connector.polled = DRM_CONNECTOR_POLL_HPD;
 250         ret = drm_connector_init(bridge->dev, &ptn_bridge->connector,
 251                         &ptn3460_connector_funcs, DRM_MODE_CONNECTOR_LVDS);
 252         if (ret) {
 253                 DRM_ERROR("Failed to initialize connector with drm\n");
 254                 return ret;
 255         }
 256         drm_connector_helper_add(&ptn_bridge->connector,
 257                                         &ptn3460_connector_helper_funcs);
 258         drm_connector_register(&ptn_bridge->connector);
 259         drm_connector_attach_encoder(&ptn_bridge->connector,
 260                                                         bridge->encoder);
 261
 262         if (ptn_bridge->panel)
 263                 drm_panel_attach(ptn_bridge->panel, &ptn_bridge->connector);
 264
 265         drm_helper_hpd_irq_event(ptn_bridge->connector.dev);
 266
 267         return ret;
 268 }
 269
 270 static const struct drm_bridge_funcs ptn3460_bridge_funcs = {
 271         .pre_enable = ptn3460_pre_enable,
 272         .enable = ptn3460_enable,
 273         .disable = ptn3460_disable,
 274         .post_disable = ptn3460_post_disable,
 275         .attach = ptn3460_bridge_attach,
 276 };
 277
 278 static int ptn3460_probe(struct i2c_client *client,
 279                                 const struct i2c_device_id *id)
 280 {
 281         struct device *dev = &client->dev;
 282         struct ptn3460_bridge *ptn_bridge;
 283         int ret;
 284
 285         ptn_bridge = devm_kzalloc(dev, sizeof(*ptn_bridge), GFP_KERNEL);
 286         if (!ptn_bridge) {
 287                 return -ENOMEM;
 288         }
 289
 290         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0, &ptn_bridge->panel, NULL);
 291         if (ret)
 292                 return ret;
 293
 294         ptn_bridge->client = client;
 295
 296         ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
 297                                                GPIOD_OUT_HIGH);
 298         if (IS_ERR(ptn_bridge->gpio_pd_n)) {
 299                 ret = PTR_ERR(ptn_bridge->gpio_pd_n);
 300                 dev_err(dev, "cannot get gpio_pd_n %d\n", ret);
 301                 return ret;
 302         }
 303
 304         /*
 305          * Request the reset pin low to avoid the bridge being
 306          * initialized prematurely
 307          */
 308         ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
 309                                                 GPIOD_OUT_LOW);
 310         if (IS_ERR(ptn_bridge->gpio_rst_n)) {
 311                 ret = PTR_ERR(ptn_bridge->gpio_rst_n);
 312                 DRM_ERROR("cannot get gpio_rst_n %d\n", ret);
 313                 return ret;
 314         }
 315
 316         ret = of_property_read_u32(dev->of_node, "edid-emulation",
 317                         &ptn_bridge->edid_emulation);
 318         if (ret) {
 319                 dev_err(dev, "Can't read EDID emulation value\n");
 320                 return ret;
 321         }
 322
 323         ptn_bridge->bridge.funcs = &ptn3460_bridge_funcs;
 324         ptn_bridge->bridge.of_node = dev->of_node;
 325         drm_bridge_add(&ptn_bridge->bridge);
 326
 327         i2c_set_clientdata(client, ptn_bridge);
 328
 329         return 0;
 330 }
 331
 332 static int ptn3460_remove(struct i2c_client *client)
 333 {
 334         struct ptn3460_bridge *ptn_bridge = i2c_get_clientdata(client);
 335
 336         drm_bridge_remove(&ptn_bridge->bridge);
 337
 338         return 0;
 339 }
 340
 341 static const struct i2c_device_id ptn3460_i2c_table[] = {
 342         {"ptn3460", 0},
 343         {},
 344 };
 345 MODULE_DEVICE_TABLE(i2c, ptn3460_i2c_table);
 346
 347 static const struct of_device_id ptn3460_match[] = {
 348         { .compatible = "nxp,ptn3460" },
 349         {},
 350 };
 351 MODULE_DEVICE_TABLE(of, ptn3460_match);
 352
 353 static struct i2c_driver ptn3460_driver = {
 354         .id_table       = ptn3460_i2c_table,
 355         .probe          = ptn3460_probe,
 356         .remove         = ptn3460_remove,
 357         .driver         = {
 358                 .name   = "nxp,ptn3460",
 359                 .of_match_table = ptn3460_match,
 360         },
 361 };
 362 module_i2c_driver(ptn3460_driver);
 363
 364 MODULE_AUTHOR("Sean Paul <seanpaul@chromium.org>");
 365 MODULE_DESCRIPTION("NXP ptn3460 eDP-LVDS converter driver");
 366 MODULE_LICENSE("GPL v2");